stoichiometric analysis of thermal decomposition of sodium bicarbonate, Lab Reports of Chemistry

Download stoichiometric analysis of thermal decomposition of sodium bicarbonate and more Lab Reports Chemistry in PDF only on Docsity! STOICHIOMETRIC ANALYSIS OF THERMAL DECOMPOSITION OF SODIUM BICARBONATE Abstract: Sodium bicarbonate undergoes a decomposition reaction when heating occurs. This reaction is essential used in our daily lives, such as when cooking and baking. We can see that sodium bicarbonate decomposes faster at a higher temperature. Carbon dioxide and water were produced during this experiment. Both gaseous disappeared into the surrounding because it is in a gaseous state and at a warm temperature. The objective of this experiment is to quantify the chemical components in sodium bicarbonate during decomposition using heat. Sodium carbonate is the best product from the reaction for both temperatures at 100°C and 200°C. However, all of the possible reactions 1,2, and 3 will produce sodium hydroxide with water, sodium oxide with water and carbon dioxide, and sodium carbonate with water and carbon dioxide, respectively, as the result of the decomposition reaction. Furthermore, reaction 3 is the best decomposition reaction for this experiment out of all the possible decomposition reactions. According to the facts, the theoretical yield for reaction 3 calculated using the mass method is nearly identical to the experimental yield, whereas theoretical yields for sodium X, sodium hydroxide, and sodium oxide are incompatible with the actual yield. In conclusion, the sodium bicarbonate was completely decomposed in the oven at a higher temperature of 200°C, the percentage yield and percentage error are quite low when compared to the decomposition reaction at 100°C. Introduction: In a chemical equation, the stoichiometric coefficient is the number written in front of atoms, ions, or molecules. On both the reactant and product sides of the equation, the numbers are used to balance the number of each type of atom. Stoichiometric coefficients are also helpful in determining the mole ratio between reactants and products. The mole ratio is important because it allows chemists to calculate how many moles of product can be made from a given number of moles of a reactant, or how many moles of reactants are required to make a given amount of product. It is used in industry, for example, to calculate the number of materials needed, estimate the amount of product produced from a given reaction, and aid in determining profitability. The decomposition reaction, as compared to the synthesis reaction. Chemical substances decompose into two or more distinct compounds. The chemical compound is stable and doesn’t decompose on its own. The temperature at which sodium bicarbonate, NaHCO3, decompose is between 100°C and 180°C (373-453 K). The rate f decomposition is time and temperature-dependent. This method has a wide range of applications in a variety of industries. Procedure: The oven was preheated to 100°C. The empty container was weighed. The mass was recorded. Sodium bicarbonate was placed in the container. The container and sodium bicarbonate were weighed, and the mass was recorded. nk WN eB The container that contains sodium bicarbonate was placed in the oven with a temperature of 100°C. The container with sodium bicarbonate was heated in the oven for 15 minutes. The container was removed from the oven. . The container with sodium bicarbonate was cooled down to room temperature. wo nna . The sample was reweighed. The mass was recorded. 10. Step 1 until 9 was repeated but the temperature of the oven was set to 200°C Result: 1) 200°C Table 2: Data of components before heat decomposition Trial 1 Trial 2 container Container +sodium bicarbonate Sodium bicarbonate Table 3: The data for components after heat decomposition Trial 1 Trial 2 Container + sodium X Sodium X 2) 100°C Table 4: Data of components before heat decomposition Trial 1 Trial 2 container Container +sodium bicarbonate Sodium bicarbonate Table 5: The data for components after heat decomposition Trial 1 Trial 2 Container + sodium X Sodium X =19¢g (Part 3) The balanced chemical equation for possible decompositions of reactions 1,2 and 3 4) sodium bicarbonate|s| + sodium hydroxide | s|+ carbon dioxide |g| NaHCOs\s| + NaOH |s|+CO2(g) 5) sodium bicarbonate|s| — sodium oxide |s|+ carbondioxide| g|+ water (g) 2 NaH COsa(s) + Na2O|s|+2CO2\g\+H20(g) 6) sodium bicarbonate |s| + sodiumcarbonate | s}+carbon dioxide| g|+ water (g) 2 NaHCOa(s) + Na2COs\s|+CO2\g|+H20(g) Molecular weight: 1) NaHCOs =84—2 NaHCOs mol 2) NaOH =40-2 NaOH mol 3) Nao =62-2_Na20 mol 4) NazCOs =106—1Na2COs mol (Part 4) The calculation for the mass product obtained from reactions 1,2, and 3 For 200°C (first trial The calculation for the mass of the product obtained if 18 g sodium bicarbonate is used: First Possible reaction 18gNaHCO3 _1molNaHCO3__1mol NaOH 40 g NaOH x x x =8.6 g NaOH 1 84gNaHCOs 1molNaHCOs3 1mol NaOH Second possible reaction 18gNaHCO3 _ 1molNaHCO3._1molNa2zO 62gNa20 3 6g a20 1 "84g NaHCOs * 2mol NaHC Os \ lmolN a20 Third possible reaction 18g NaHCO3 1mol NaHC Os | 1mol Na2CO3 106g NazCOs 1 84gNaHCOs 1molNaHCO3z 1molNazCO3 =8.6gN azCO3 For 200°C (second trial The calculation for the mass of the product obtained if 18 g sodium bicarbonate is used: First Possible reaction 18g NaHCO3 1mol NaHCOs |, 1mol NaOH 40 g NaOH 1 84gNaHCOs 1molNaHCOs3 1mol NaOH =8.6 g NaOH Second possible reaction 18gNaHC Os | 1mol NaHCOs | 1molNazO x S2gNaz0 1 84gNaHCOs 2molNaHCOz 1molNazO =8.6gNa2z0 Third possible reaction 18gNaHCO3_1molNaHCO3_ 1molNazCOs3 | 106g Na2zCO3 x =8.6gN azCO3 1 84gNaHCOs 1molNaHCO3z 1molNazCO3 For 100°C (first trial The calculation for the mass of the product obtained if 19 g sodium bicarbonate is used: First Possible reaction 18gNaHCO3_ 1molNaHCO3__1molNaOH 40 g NaOH x x x =8.6 g NaOH 1 84gNaHCOs 1molNaHCOs3 1mol NaOH Second possible reaction 18gNaHCO3_1molNaHCO3._1molNa2zO 62gNa20 3 69 a20 1 84g NaHCO3 * > mol NaHC Os 1molN azO Third possible reaction 18gNaHCO3_1molNaHCO3_ 1molNazCOs3 | 106g Na2zCO3 x x x =8.6gN azCO3 1 84gNaHCOs 1molNaHCO3z 1molNazCO3 For 100°C (second trial The calculation for the mass of the product obtained if 18 g sodium bicarbonate is used: First Possible reaction 18gNaHC Os | 1mol NaHCO 1mol NaOH 40 g NaOH x x =8.6 g NaOH 1 84gNaHCOs 1molNaHCOs3 1mol NaOH Second possible reaction 18gNaHCO3_ 1molNaHCO3__1molNa2zO 62gNa20 _3 6 0Na20 1 "84g NaHCOs * 2mol NaHC Os * 1molN a20 Third possible reaction 18g NaHCO3 1mol NaHC Os | 1mol Na2CO3 106g NazCOs 1 84gNaHCOs 1molNaHCO3z 1molNazCO3 =8.6gN azCO3 Discussion: This experiment aims to determine the decomposition reaction and quantify the chemical components in sodium bicarbonate during decomposition by heating the sodium bicarbonate in an oven at 200°C and 100°C. The sodium X mass that remains after the decomposition process is used to determine which decomposition reactions are possible. When the theoretical yield is close to the actual yield value, this reaction is said to be possible. Tables 6 and 7 show the results of the mass of sodium bicarbonate before decomposition at 200°C and 100°C, respectively. Using the formula mass obtained for the first and second trial at 200°C are 18g and 19g while for 100°C are 19g and 17g respectively. The mass production of unknown sodium can be calculated using all three possible reactions based on the calculated values in Tables 6 and 7. The mass of sodium hydroxide can get in reaction 1, the mass of sodium oxide in reaction 2, and sodium bicarbonate in the final reaction. The mass of sodium X, which represents unknown sodium after decomposition, was calculated using the formula in tables 8 and 9. The first and second trials of table 8 at 200°C yielded 11g and 13g of mass, respectively, while the first and second trials of table 9 yielded 18g and 15g of mass. A formula was used to calculate the theoretical mass of sodium X, which includes sodium hydroxide, sodium oxide, and sodium bicarbonate. The mass of NaOH for the first trial in the first reaction at 200°C is 8.60g. 18g NaHCO3 from the mass of sodium bicarbonate was calculated before the start of the decomposition reaction. Meanwhile, the molecular weight of the given NaHCO3 compound is 84 g/mol. In reaction 1, one mole NaHCO3 reacted to produce one mole of NaOH. Then multiply it by the molecular weight of NaOH, which is 40g/mol to get 8.60g of NaOH. When sodium bicarbonate is heated to 200°C, it produces sodium hydroxide and carbon dioxide, which is the first possible decomposition reaction. However, the molecular weight of carbon dioxide is not included in the calculation. This is because when sodium hydroxide cooled to room temperature, the carbon dioxide escapes into the surrounding. The mass of all possible sodium X at 200°C and 100°C for the first and second trials for each of the decomposition reactions can also be determined using the same method as before. Because it fits the experimental yield, the third decomposition reaction is the best chemical decomposition reaction for this experiment. So, the sodium X is sodium carbonate, Na2CO3. The mass obtained for the first and second trials for each 100°C and 200°C is nearly the same as the experimental yield. 11.36g is almost near to 11g. The percentage yield is used to express the difference between the actual yield and the theoretical maximum yield. The percentage yield for 200°C and 100°C are 103% and 145% respectively. Both reactions give a percentage over 100%. Some impurities might occur during the experiment such as sodium bicarbonate located in the refrigerator for too long until the sodium bicarbonate becomes lumpy. By taking the average percentage error for both trials are 2.7% and 45.2% respectively. Conclusion: To summarise, sodium hydroxide, sodium oxide, and sodium carbonate are the three main products produced. When sodium bicarbonate is heated in the oven at different temperatures, such as 100°C and 200°C, each of these products is created. By comparing the theoretical and experimental yields, sodium carbonate is the best product that indicates sodium X in reaction 3. After the experiment, the mass of sodium carbonate obtained was the most similar to the experimental yield.